package com.itheima.test2;

public class Test {

    public static void main(String[] args) {
        Outer.i=10;
        System.out.println(Outer.i);
        Outer.Inner inner =new  Outer.Inner();
        inner.y=20;
        System.out.println(inner.y);
        //Outer.Inner.sing();
    }
}


class Outer{
    static int i;
    static A a;
    public void useA(){
       // Inner inner= new Inner();
        Inner.sing();
    }
     static class Inner{
        int y;
        public   static   void sing() {
            System.out.println("来一首");
        }
    }
}
class A {
  private int i;
  public void sing(){

  }
  public static void jump(){

  }
}